How can spray paint and wall paint be removed from a large surface area of cement if pressure wash and graffiti remover did not work?

Slop on some paint remover. Make sure the concrete is completely dry first so that the paint remover can have some time to work before getting wet. Let it sit for the recommended time then use the spray washer again. Answer Another option is sandblasting which is the method used in most municipalities to remove graffiti from bridges, buildings and so forth.

Also any paint brush cleaner will work (found at local handy store). This past weekend I was spray painting a picture frame and I got a large amount of silver spray paint on my drive way. I just poured it on the spots and scrubbed lightly with an old rag. Once pouring it on, you will immediately see it washing away. Once finished scrubbing, and the spray paint is all gone, just wash it all away with your hose. Make sure not to get any on your skin. Paint brush cleaner is equivalent to lighter fluid if in contact with skin. Paint brush cleaner will also catch on fire, so make sue not to have any flames around the area of cause.